Process for producing printing-plates of slight weight.



UNITED STATES PATENT orrron SIGVALD ALFREDCHRISTIANIKRISTENSEN, 0F FREDERIKSBERG, NEAR COPENHAGEN, 'DENMARK.

PROCESS FOR PRODUCING PRINTING-*PLATES OF"SLIGHT WEIGHT.

1 10 Drawing.

To all wk omit may concern: 7 Be it knownthat I, SIGVALD ALFRED CHRIS- TIAN KRIs'rEN SEN, stereotypist, subject of the King of Denmark, residing at2 .Neumannsvej, Frederiksberg, near Copenhagen, .Denmark, have invented certain new and useful Improvements in Processes for Producing Printing-Plates of Slight WVeight, .of which the following is a specification.

The great demands made to .the daily press and the illustrated press in respect to pictorial recordsofthings and events, immediately after they have become interesting or have happened, have made it necessary for the printing establishments to acquire, very quickly, av printing block of the interesting object or event concerned. It has been attempted, heretofore, to satisfy this demand by producing, at a graphic establishment as near as possible to the locality where the object concerned is found or the event has happened, a number of prints, for instance photographic ones, from a. photographic negative taken of the object or the event and to send such photograhps to the various printing houses or to other graphic establishments, and each of these would then, independently, produce from the print the blocks requiredor paper fiongs for stereotyping have been sent, and the printing houses or other graphic establishments have then, by stereotyping, produced the requisite printing blocks from the flongs. An essentially more complete solution of the problem it would be, however, if the graphic establishment producing the original record, for instance a photographic negative of the object or event concerned, were enabled to produce, quickly and with certainty, a number of fully finished printing plates, adapted to be forwarded quickly by mail, 2'. e. by ordinary letter mail. Such plates are required, according to the nature of the matter, to be very light besides possessing the properties desirable from a purely typographic point of view, for instance to be flexible, in order that they may be used in ordinary presses or in rotary presses, as the case may be. It has been proposed, as a solution of this problem, to use a layer of unsized paper coated by a paste consisting of a metal powder stirred into a powerful adhesive, such paste possessing the property of becoming quite hard when drying. The material thus prepared would be rapped I Specification of Letters-Patent.

Patented AprA, 1916.

.into a matrix by meansof a brush, and it would then be coated, at the-rear side, by some suitable substance.

The present invention, on the contrary,

has'for'its object that the saidunsized-paper adhere to a thin sheetof some .plastic sub stance, for instance celluloid, and then coated with av pasteof the said-kind where- 1 after the material thus produced is impressed intov a matrixsuitable for this-purposeby using, if necessary, a slight heating in connection with the pressure. Hereby a possibility is opened for the production, in really great quantities, of printing plates of slight weight. When celluloid is used as a backing, it will be attained, by employing heating and pressure, that the coating of tissue paper will be able to adhere to the backing without adhesives having to be used and thus the smoothest possible surface will be attained. The layer of tissue paper is coated, preferably, by a paste consisting of aluminium powder stirred into water-glass. The sheet thus prepared is imprinted in a matrix of the requisite fineness and hardness and, after shipment, the plate thus finished may be placed in the plane or cylindrical form, it being simply pasted on the form,

previously cast with blank depressed porplate. Y

The material used for producing the plates I may be manufactured and kept in stock so that it is only necessary to impress the material on the matrix, heating it slightly perhaps, in order to produce any number of plates, fully finished. Thus the production of the plates, as well of their fitting into position, requires but vary short time.

As a die for the plates there may be used a lead matrix stamped from a book-plate of the usual kind. Such a matrix, however, will hardly be sufficiently fine or .hard enough to stand the stamping of the plates. The best result is attained, according to this invention, by a matrix being stamped in easily fusible metal from the original printing plate, preferably a metal melting at about 100 Centigrade and, suitably, being placed as a coating on a lead plate. This matrix is now stereotyped, there being used, preferably, in producing the paper flong a suitable paste, for instance the same as the one used for the plates. In the paper fiong thus produced, a negative cast is now made, in known manner, of type-metal or a harder alloy, this cast forming an excellent matrix for stamping the printing plates in the above described manner. The lead plates with covering of easily fusible metal used in the preparatory stamping may be manufactured in quantities for keeping in stock.

The matrix for stamping the printing platesmay be made plane or cylindrical as desired, and the latter shape has the advantage of making it easy to eifect a perfectly mechanical manifolding of the final printing plates on a band of the said material drawn past the cylindrical rotating matrix and pressed against it.

Having now particularly described and ascertained the nature of my said invention n and in what manner the same is to be performed, I declare that what I claim is The process for producing, in quantities, printing plates of slight weight, said process consisting in first causing, solely by heat and pressure, a layer of tissue paper to adhere to a backing of celluloid, second coat- SIGVALD ALFRED CHRISTIAN KRISTENSEN.

WVitnesses :7

CAnnFox MAIELE, JULIUS LEHMANN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents v Washington, D. C. 

